1. Field of the Invention
This invention relates to metal roofing and siding panel mounting systems, and more particularly to such a mounting system employing panel penetrating fasteners for securing both the overlapping side edges of adjacent panels and the central portions of individual panels to underlying support structure.
2. Description of the Prior Art
Metal building panels of the type employed for the construction of external building walls and roofs are conventionally relatively large to minimize the number of side and end joints in the completed wall or roof. Such roof and wall panels, herein referred to as building panels or panels, may be up to 30 feet or more in length and 38 inches or more in overall width and are mounted to underlying support members such as roofing purlins or wall girts (hereinafter purlins) by suitable penetrating fasteners such as ring shank or screw shank nails or drill screws with sealing washers. Such building panels are conventionally formed with longitudinally extending ribs for strength and decorative purposes, one such building panel being illustrated, for example, in U.S. Pat. No. 205,008.
The width of such conventional building panels may make it necessary to secure the individual panels to the underlying purlins at points intermediate the panel edges as well as at the edge joints, and the heads of the penetrating fasteners are visible from the exterior of the building structure. Such exposed fastener heads detract from the building appearance, particularly if the color of the heads and insulating washer material does not identically match that of the building panels.
It has been proposed, for example in U.S. Pat. No. 4,321,780, to conceal the fastener heads used to mount metal building panels by providing the panels with an inwardly concave reinforcing rib through which the fasteners are driven. Each fastener is passed through a mounting clip which projects upwardly into the outwardly open reinforcing rib channel, and a shaped capping strip is releasably mounted on the mounting clips in outwardly spaced relation from the bottom of the rib channel. This arrangement, however, requires a different construction at the edges of adjacent panels so that a non-uniform appearance is given to the finished wall or roof. Further, when this arrangement is employed in a roofing assembly, water will inherently penetrate to the bottom of the reinforcing rib channel and, unless a tight seal is provided between the adjacent surfaces of the building panel and mounting clip, moisture can be drawn by capillary action to the fastener opening through the building panel and ultimately result in corrosion and/or leakage.
It is also well known to use elongated cap or batten strips to cover the edge joint between adjacent panels in a metal building panel roof or wall structure. U.S. Pat. No. 3,327,443 and U.S. Pat. No. 2,428,361 illustrate this type of construction. Such building panels, however, are normally relatively narrow and do not disclose any means for securing individual panels to the underlying purlins intermediate the panel edges. Further, such structures normally do not employ an overlapping type seam between adjacent building panels but rather provide some structure secured directly to the underlying purlin for anchoring the adjacent panel edges.